Harnessing big data to improve healthcare quality has become something of a holy grail for regulators. While England’s Care Quality Commission is an acknowledged leader, the applicant has shown that its use of big data has not improved regulatory effectiveness, raising wider questions about the potential utility of this approach. In response, this pilot project will explore how other countries’ healthcare regulators use big data and will draw on comparisons with England’s experience, which has already been documented by the applicant and others, to identify and help understand common problems and opportunities for improvement. To that end this project will combine desk-based research and qualitative interviews and workshops with regulators and other stakeholders to: 1) Map the use of big data for healthcare quality regulation across all 31 high-income OECD countries; 2) Explore four country case-studies reflecting a range of data-usage patterns and payer-provider-regulator configurations, in order to develop hypotheses about the factors shaping the use and effectiveness of big data; 3) Lay the groundwork for a larger follow-up study by securing data-access and collaboration agreements to test those hypotheses and assess the barriers to improving healthcare quality regulation with big data.